Alright I finally made it!! @$#% So if anyone stumbles on this tread at least it will be closed:).
So to manage what i wanted to do i created a custom event in the BP I needed the showed message to be erased as soon as the line trace would equal to false. And in my_character BP I did a"Get all actor from class" node of the BP I was aiming the cast to and called that event witch deleted or reseted the AA text Render componnet… ET VOILA@@@!!! Closed hahaha
Cheers!!